Iteratively optimize an N-body gravitational simulation from O(N^2) to O(N log N) with correctness…

Iteratively optimize an N-body gravitational simulation from O(N^2) to O(N log N) with correctness…: a task in Long-Horizon Terminal-Bench (LHTB) (Harbor dataset). Optimize a 2D N-body gravitational simulation from a naive O(N²) implementation to achieve significant speedups at increasing particle…